Provisioning transmission pools for inter-carrier prose direct discovery

ABSTRACT

A method in a wireless device is disclosed. The method comprises receiving one or more resource pool configurations for a particular discovery carrier, the one or more resource pool configurations comprising information indicating one or more of resource elements and subframes that the wireless device should use to monitor for incoming discovery messages and transmit outgoing discovery messages, the received one or more resource pool configurations comprising at least a first resource pool configuration received from a serving network node of the wireless device operating in Time Division Duplex (TDD) mode. The method comprises determining which of the received one or more resource pool configurations that the wireless device should use to monitor for incoming discovery messages and transmit outgoing discovery messages.

PRIORITY

This application is a continuation of U.S. patent application Ser. No.15/232,985 filed on Aug. 10, 2016, now U.S. Pat. No. 10,237,809 B2,which claims the benefit of U.S. Provisional Application 62/205,363filed on Aug. 14, 2015, the entire disclosures of which are herebyincorporated by reference.

TECHNICAL FIELD

The present disclosure relates, in general, to wireless communicationsand, more particularly, to provisioning transmission pools forinter-carrier ProSe direct discovery.

BACKGROUND

In device-to-device (D2D) communications, user equipment (UEs) inproximity of each other can establish a direct radio link tocommunicate. For this reason, this technology is also known as LTEdirect in the literature or as Proximity Service (ProSe) in the 3rdGeneration Partnership Project (3GPP) standardization body.

Exploiting a D2D link may allow for very high bit rates, low delays andlow power consumption. This makes D2D technology amenable to new typesof wireless peer-to-peer services. End-users are increasingly interestedin sharing content and/or services with other users in theirsurroundings, and in establishing peer-to-peer connections to exchangelarge amounts of data, share interests and applications, and othersimilar activities. D2D technology also has applications in the fieldsof national security and public safety. This is because D2D technologymay, for example, allow network connectivity to remote UEs in disasterareas via public safety dispatchers (e.g., police, fire brigades,ambulances, etc.) while enjoying the benefits of broadband capabilities.

A basic requirement for network nodes supporting D2D communications isthat they should be able to coexist with legacy RAN nodes as the D2Dfeature is gradually introduced into the existing RAN infrastructure.Consequently, D2D-related functionalities should be implemented takinginto account existing LTE infrastructure that can assist D2D UEs inestablishing a reliable and secure D2D radio link layer that can coexistwith the ordinary cellular link layer. Certainly, D2D communications canalso happen in an ad-hoc and autonomous fashion in case the cellularnetwork is damaged, or if D2D-capable UEs do not have network coverage.

D2D-type communication was first standardized under the umbrella of 3GPPin Release 12. In Release 12, the 3GPP standardization bodydistinguishes between two different types of services: ProSe DirectCommunication and ProSe Direct Discovery. In ProSe Direct Communication,UEs in proximity of each other establish a direct user plane connection.In ProSe Direct Discovery, UEs transmit in broadcast and monitordiscovery announcements to become aware of the type of content and/orservice each UE can share in D2D fashion, as well as the proximitybetween each other. Enhanced D2D-related features are currently understandardization in 3GPP Release 13. These enhancements include enablingUE-to-Network relay, support for D2D discovery in multiple carriers andout-of-coverage carriers, QoS and priorities aspects.

For ProSe Direct Communication, two different operative modes arespecified in 3GPP: mode 1 and mode 2. In mode 1, a UE in RRC_CONNECTEDmode requests D2D resources and the eNodeB (eNB) grants them viaPhysical Downlink Control Channel (PDCCH) (DCIS). This is similar towhat happens for cellular uplink (UL) grants. In mode 2, a UEautonomously selects resources for transmission from a pool of availableresources that the eNB provides in broadcast via Session InformationBlock (SIB) 18 (SIB18) for transmissions on carriers other than thePrimary Cell (PCell) or via dedicated signaling for transmission on thePCell.

Mode 1 provides a more accurate scheduling from the eNB that can bettercontrol the resources actually used for ProSe communication. Mode 1 alsoprovides the UE with a less-interfered resource allocation. Mode 2, onthe other hand, requires less implementation complexity and lesssignaling from the eNB at the expense of possible higher interference.In addition, Mode 1 is only applicable to UEs in RRC_CONNECTED, whilemode 2 communications can also be performed by UEs in RRC_IDLE.

Regardless of the mode employed, ProSe communication takes place in thePhysical Sidelink Shared Channel (PSSCH) during the so-called SC period.The characteristics of the PSSCH (e.g., length, System Frame Number(SFN) offset, etc.) are signaled by the ProSe discovery carriers. Withinthe SC period, each PSSCH transmission is preceded by the SchedulingAssignment (SA) period, which takes place in a dedicated PhysicalSidelink Control Channel (PSCCH). In the PSCCH, transmitting UEs informother UEs in the surrounding area on parameters of the following PSSCHdata transmission, including Physical Resource Blocks (PRBs), timepattern, and modulation and coding scheme (MCS) parameters. Thisinformation helps monitoring UEs correctly perform decoding.

For ProSe Direct Discovery, two different operative modes are specifiedin 3GPP: type 1 and type 2B. Similar to mode 1 communication in ProSeDirect Communication, in type 2B discovery the eNB provides grants viadedicated Radio Resource Control (RRC) signaling. Similar to mode 2communication in ProSe Direct Communication, in type 1 discovery a UEautonomously selects discovery resources. These discovery resources areprovided either via dedicated signaling for UEs in the PCell and inRRC_CONNECTED, or acquired from SIB19 for UEs that are in RRC_IDLE. Morespecifically, in type 1 discovery the network provides one or moreresource pools. Each resource pool is characterized by a set of PRBs andsubframes in which discovery can actually take place. The UE thenautonomously selects one of such pools either randomly or on the basisof Reference Signal Received Power (RSRP) measurements related to thedifferent pools. Not all of the resources available in the discoverypool, however, are ultimately used for discovery (i.e., the exacttime/frequency resources to use within the pool are selected randomly,and each resource has an equal probability of being selected). Inparticular, transmission of a discovery Medium Access Control (MAC)Protocol Data Unit (PDU) takes place in one subframe and two PRBs.

In some cases, discovery messages are transmitted in the PhysicalDownlink Shared Channel (PDSCH) during the discovery period. The PDSCHconfiguration (e.g., length, SFN offset, etc.) is provided as part ofthe resource pool configuration. To this end, the subframes within thediscovery period that can potentially be used for discovery transmission(or retransmission) are signaled via a bitmap. Within the bitmap, 0 and1 indicate that this specific subframe is allowed for transmission or isnot allowed for transmission, respectively. As described above, the UEhas to select one of such subframes and two PRBs for transmission of adiscovery message. Each pool may be configured with different bitmapvalues and bitmap lengths, and can be repeated for a maximum of 5 timeswithin the discovery period. A discovery message can also beretransmitted within the pool using a different puncturing of theencoder according to the principles of soft combining.

A fundamental property of wireless communication is the fact thatconstructing a device which can send and transmit on the same frequencyat the same time is prohibitively expensive. Instead, various duplexschemes are used. One example duplex scheme is Frequency Division Duplex(FDD). FDD uses two carriers separated by a certain number of MHz. Thisallows a device to transmit on one carrier (the uplink (UL) carrier) andreceive on another (the downlink (DL) carrier) at the same time. Thus, acarrier designated for FDD consists of two carriers (one UL and one DL),and are referred to as paired carriers. If the UE knows the frequency ofa UL (or DL) carrier, it also knows the corresponding paired DL (or UL)carrier frequency.

Another example duplex scheme is Time Division Duplex (TDD). TDD usesonly one carrier, which is divided in time creating slots. Some slotsare used for transmission (uplink subframes) and others are used forreception (downlink subframes).

D2D on a FDD carrier by design only uses the uplink carrier. In otherwords, UEs both transmit and receive on the uplink carrier.

Release 13 does not limit ProSe discovery carrier transmission to thePCell. ProSe discovery transmission can take place in any carrier,including, for example, a Secondary Cell (SCell), a non-serving carrier,a carrier belonging to another eNB (or even to another Public LandMobile Network (PLMN)), or a preconfigured carrier that is used forpublic safety operations. Resource configurations for transmitting andmonitoring on a non-PCell carrier can be provided in a variety of ways.For example, in cases where TDD mode is used, resource configurationsfor transmitting and monitoring on a non-PCell carrier can be providedeither by the carrier itself via broadcast signaling (e.g., systeminformation such as SIB19) or via a serving cell in the serving eNB withdedicated signaling or broadcast signaling. As another example, in caseswhere FDD mode is used, resource configurations for transmitting andmonitoring on a non-PCell carrier can be provided either by a pairedcarrier associated with a particular discovery carrier via broadcastsignaling (e.g., system information such as SIB19) or via a serving cellin the serving eNB with dedicated signaling or broadcast signaling.

This implies that coordination between different eNBs or different PLMNsshould be supported to allow the serving eNB to provide resourceconfigurations for transmitting and/or monitoring on other carriers thatdo not belong to the serving eNB to which the UE is connected or onwhich the UE is camping.

SUMMARY

To address the foregoing problems with existing approaches, disclosed isa method in a wireless device. The method comprises receiving one ormore resource pool configurations for a particular discovery carrier,the one or more resource pool configurations comprising informationindicating one or more of resource elements and subframes that thewireless device should use to monitor for incoming discovery messagesand transmit outgoing discovery messages, the received one or moreresource pool configurations comprising at least a first resource poolconfiguration received from a serving network node of the wirelessdevice operating in Time Division Duplex (TDD) mode. The methodcomprises determining which of the received one or more resource poolconfigurations that the wireless device should use to monitor forincoming discovery messages and transmit outgoing discovery messages.

In certain embodiments, the method may comprise determining whether thereceived one or more resource pool configurations for the particulardiscovery carrier include a second resource pool configuration receivedvia system information of the particular discovery carrier. The methodmay comprise upon determining that the received one or more resourcepool configurations for the particular discovery carrier includes thesecond resource pool configuration received via system information ofthe particular discovery carrier, using the second resource poolconfiguration to monitor for incoming discovery messages and transmitoutgoing discovery messages.

In certain embodiments, the method may comprise determining whether theparticular discovery carrier contains system information. The method maycomprise upon determining that the particular discovery carrier does notcontain system information, determining whether the wireless device islocated at a cell edge between in-coverage and out-of-coverage for theparticular discovery carrier. The method may comprise upon determiningthat the wireless device is not located at a cell edge betweenin-coverage and out-of-coverage for the particular discovery carrier,determining that the first resource pool configuration received from theserving network node of the wireless device should not be used tomonitor for incoming discovery messages and transmit outgoing discoverymessages. The method may comprise upon determining that the wirelessdevice is located at a cell edge between in-coverage and out-of-coveragefor the particular discovery carrier, using the first resource poolconfiguration received from the serving network node of the wirelessdevice to monitor for incoming discovery messages and transmit outgoingdiscovery messages. Determining whether the wireless device is locatedat the cell edge between in-coverage and out-of-coverage for theparticular discovery carrier may be based on at least one of: whethersystem information is not received by the wireless device for a firstduration; and whether an S-criterion used to determine when the UE isout-of-coverage or in-coverage with respect to the particular discoverycarrier is not fulfilled for a second duration.

In certain embodiments, the method may comprise determining whethersystem information of the particular discovery carrier is broadcast. Themethod may comprise upon determining that system information of theparticular discovery carrier is not broadcast, using the first resourcepool configuration received from the serving network node of thewireless device to monitor for incoming discovery messages and transmitoutgoing discovery messages. The method may comprise receiving anindication from the serving network node that the particular discoverycarrier does not support system information. The method may compriseupon determining that system information of the particular discoverycarrier is broadcast, determining whether the system information of theparticular discovery carrier includes a second resource poolconfiguration. The method may comprise upon determining that the systeminformation of the particular discovery carrier does not include thesecond resource pool configuration, using the first resource poolconfiguration received from the serving network node of the wirelessdevice to monitor for incoming discovery messages and transmit outgoingdiscovery messages.

Also disclosed is a wireless device. The wireless device comprises oneor more processors. The one or more processors are configured to receiveone or more resource pool configurations for a particular discoverycarrier, the one or more resource pool configurations comprisinginformation indicating one or more of resource elements and subframesthat the wireless device should use to monitor for incoming discoverymessages and transmit outgoing discovery messages, the received one ormore resource pool configurations comprising at least a first resourcepool configuration received from a serving network node of the wirelessdevice operating in Time Division Duplex (TDD) mode. The one or moreprocessors are configured to determine which of the received one or moreresource pool configurations that the wireless device should use tomonitor for incoming discovery messages and transmit outgoing discoverymessages.

Also disclosed is a method in a network node. The method comprisesdetermining a first resource pool configuration for a particulardiscovery carrier, the first resource pool configuration comprisinginformation indicating one or more of resource elements and subframesthat a wireless device operating in Time Division Duplex (TDD) modeshould use to monitor for incoming discovery messages and transmitoutgoing discovery messages. The method comprises communicating thefirst resource pool configuration to the wireless device. The methodcomprises configuring the wireless device to use one of the firstresource pool configuration or a second resource pool configurationcommunicated via system information of the particular discovery carrier.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thesecond resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the wireless devicereceives both the first resource pool configuration and the secondresource pool configuration.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to not usethe first resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the particulardiscovery carrier does not contain system information and the wirelessdevice is not located at a cell edge between in-coverage andout-of-coverage for the particular discovery carrier. In certainembodiments, configuring the wireless device to use one of the firstresource pool configuration or the second resource pool configurationmay comprise configuring the wireless device to use the first resourcepool configuration to monitor for incoming discovery messages andtransmit outgoing discovery messages if the particular discovery carrierdoes not contain system information and the wireless device is locatedat a cell edge between in-coverage and out-of-coverage for theparticular discovery carrier.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if system informationof the particular discovery carrier is not broadcast. The method maycomprise communicating an indication to the wireless device that theparticular discovery carrier does not support system information. Incertain embodiments, configuring the wireless device to use one of thefirst resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the systeminformation of the particular discovery carrier is broadcast but doesnot include the second resource pool configuration.

Also disclosed is a network node. The network node comprises one or moreprocessors. The one or more processors are configured to determine afirst resource pool configuration for a particular discovery carrier,the first resource pool configuration comprising information indicatingone or more of resource elements and subframes that a wireless deviceoperating in Time Division Duplex (TDD) mode should use to monitor forincoming discovery messages and transmit outgoing discovery messages.The one or more processors are configured to communicate the firstresource pool configuration to the wireless device. The one or moreprocessors are configured to configure the wireless device to use one ofthe first resource pool configuration or a second resource poolconfiguration communicated via system information of the particulardiscovery carrier.

Also disclosed is a method in a wireless device. The method comprisesreceiving one or more resource pool configurations for a particulardiscovery carrier, the one or more resource pool configurationscomprising information indicating one or more of resource elements andsubframes that the wireless device should use to monitor for incomingdiscovery messages and transmit outgoing discovery messages, thereceived one or more resource pool configurations comprising at least afirst resource pool configuration received from a serving network nodeof the wireless device operating in Frequency Division Duplex Mode (FDD)mode. The method comprises determining which of the received one or moreresource pool configurations that the wireless device should use tomonitor for incoming discovery messages and transmit outgoing discoverymessages.

In certain embodiments, the method may comprise determining whether thereceived one or more resource pool configurations for the particulardiscovery carrier includes a second resource pool configuration receivedvia system information of a paired carrier associated with theparticular discovery carrier. The method may comprise upon determiningthat the received one or more resource pool configurations for theparticular discovery carrier includes the second resource poolconfiguration received via system information of the paired carrierassociated with the particular discovery carrier, using the secondresource pool configuration to monitor for incoming discovery messagesand transmit outgoing discovery messages.

In certain embodiments, the method may comprise determining whether thepaired carrier associated with the particular discovery carrier containssystem information. The method may comprise upon determining that thepaired carrier associated with the particular discovery carrier does notcontain system information, determining whether the wireless device islocated at a cell edge between in-coverage and out-of-coverage for theparticular discovery carrier. The method may comprise upon determiningthat the wireless device is not located at a cell edge betweenin-coverage and out-of-coverage for the particular discovery carrier,determining that the first resource pool configuration received from theserving network node of the wireless device should not be used tomonitor for incoming discovery messages and transmit outgoing discoverymessages. The method may comprise upon determining that the wirelessdevice is located at a cell edge between in-coverage and out-of-coveragefor the particular discovery carrier, using the first resource poolconfiguration received from the serving network node of the wirelessdevice to monitor for incoming discovery messages and transmit outgoingdiscovery messages. Determining whether the wireless device is locatedat the cell edge between in-coverage and out-of-coverage for theparticular discovery carrier may be based on at least one of: whethersystem information is not received by the wireless device for a firstduration; and whether an S-criterion used to determine when the wirelessdevice is out-of-coverage or in-coverage with respect to the particulardiscovery carrier is not fulfilled for a second duration.

In certain embodiments, the method may comprise determining whethersystem information of a paired carrier associated with the particulardiscovery carrier is broadcast. The method may comprise upon determiningthat system information of the paired carrier associated with theparticular discovery carrier is not broadcast, using the first resourcepool configuration received from the serving network node of thewireless device to monitor for incoming discovery messages and transmitoutgoing discovery messages. The method may comprise receiving anindication from the serving network node that the paired carrierassociated with the particular discovery carrier does not support systeminformation. The method may comprise upon determining that systeminformation of the paired carrier associated with the particulardiscovery carrier is broadcast, determining whether the systeminformation of the paired carrier associated with the particulardiscovery carrier includes a second resource pool configuration. Themethod may comprise upon determining that the system information of thepaired carrier associated with the particular discovery carrier does notinclude the second resource pool configuration, using the first resourcepool configuration received from the serving network node of thewireless device to monitor for incoming discovery messages and transmitoutgoing discovery messages.

Also disclosed is a wireless device. The wireless device comprises oneor more processors. The one or more processors are configured to receiveone or more resource pool configurations for a particular discoverycarrier, the one or more resource pool configurations comprisinginformation indicating one or more of resource elements and subframesthat the wireless device should use to monitor for incoming discoverymessages and transmit outgoing discovery messages, the received one ormore resource pool configurations comprising at least a first resourcepool configuration received from a serving network node of the wirelessdevice operating in Frequency Division Duplex Mode (FDD) mode. The oneor more processors are configured to determine which of the received oneor more resource pool configurations that the wireless device should useto monitor for incoming discovery messages and transmit outgoingdiscovery messages.

Also disclosed is a method in a network node. The method comprisesdetermining a first resource pool configuration for a particulardiscovery carrier, the first resource pool configuration comprisinginformation indicating one or more of resource elements and subframesthat a wireless device operating in Frequency Division Duplex (FDD) modeshould use to monitor for incoming discovery messages and transmitoutgoing discovery messages. The method comprises communicating thefirst resource pool configuration to the wireless device. The methodcomprises configuring the wireless device to use one of the firstresource pool configuration or a second resource pool configurationcommunicated via system information of a paired carrier associated withthe particular discovery carrier.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thesecond resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the wireless devicereceives both the first resource pool configuration and the secondresource pool configuration.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to not usethe first resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the paired carrierassociated with the particular discovery carrier does not contain systeminformation and the wireless device is not located at a cell edgebetween in-coverage and out-of-coverage for the particular discoverycarrier. In certain embodiments, configuring the wireless device to useone of the first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the paired carrierassociated with the particular discovery carrier does not contain systeminformation and the wireless device is located at a cell edge betweenin-coverage and out-of-coverage for the particular discovery carrier.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if system informationof the paired carrier associated with the particular discovery carrieris not broadcast. The method may comprise communicating an indication tothe wireless device that the paired carrier associated with theparticular discovery carrier does not support system information. Incertain embodiments, configuring the wireless device to use one of thefirst resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the systeminformation of the paired carrier associated with the particulardiscovery carrier is broadcast but does not include the second resourcepool configuration.

Also disclosed is a network node. The network node comprises one or moreprocessors. The one or more processors are configured to determine afirst resource pool configuration for a particular discovery carrier,the first resource pool configuration comprising information indicatingone or more of resource elements and subframes that a wireless deviceoperating in Frequency Division Duplex (FDD) mode should use to monitorfor incoming discovery messages and transmit outgoing discoverymessages. The one or more processors are configured to communicate thefirst resource pool configuration to the wireless device. The one ormore processors are configured to configure the wireless device to useone of the first resource pool configuration or a second resource poolconfiguration communicated via system information of a paired carrierassociated with the particular discovery carrier.

Certain embodiments of the present disclosure may provide one or moretechnical advantages. For example, certain embodiments mayadvantageously avoid wireless device misbehavior when the wirelessdevice receives concurrent and different resource pool provisioning fromdifferent sources for transmission/reception applicable to the samediscovery carriers. As another example, certain embodiments may reducethe amount of signaling that needs to be sent over the air, which mayadvantageously allow a wireless device to save battery because it doesnot need to continuously monitor system information from the particulardiscovery carrier. As still another example, the various embodimentsdescribed herein may be implemented in both systems using TDD andsystems using FDD. Other advantages may be readily apparent to onehaving skill in the art. Certain embodiments may have none, some, or allof the recited advantages.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the disclosed embodiments and theirfeatures and advantages, reference is now made to the followingdescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a block diagram illustrating an embodiment of a network, inaccordance with certain embodiments;

FIG. 2 is a flow diagram of a method in a wireless device, in accordancewith certain embodiments;

FIG. 3 is a flow diagram of a method in a network node, in accordancewith certain embodiments;

FIG. 4 is a flow diagram of a method in a wireless device, in accordancewith certain embodiments;

FIG. 5 is a flow diagram of a method in a network node, in accordancewith certain embodiments;

FIG. 6 is a schematic block diagram of an exemplary wireless device, inaccordance with certain embodiments;

FIG. 7 is a schematic block diagram of an exemplary network node, inaccordance with certain embodiments;

FIG. 8 is a schematic block diagram of an exemplary radio networkcontroller or core network node, in accordance with certain embodiments;

FIG. 9 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments; and

FIG. 10 is a block schematic of an exemplary network node, in accordancewith certain embodiments.

DETAILED DESCRIPTION

As described above, ProSe discovery carrier transmission is not limitedto the PCell, and can take place in any carrier (e.g., an SCell, anon-serving carrier, a carrier belonging to another eNB (or to anotherPLMN), or a preconfigured carrier that is used for public safetyoperations). The resource pool configurations for transmitting andmonitoring on a non-PCell carrier can be provided by a variety ofsources. The sources of the resource pool configurations may varydepending on whether TDD or FDD is being used. For example, when TDD isused, the resource pool configurations can be provided either by theparticular discovery carrier itself via system information or via aserving cell in the serving eNB with dedicated signaling or broadcastsignaling. When FDD is used, the resource pool configurations can beprovided either by a paired carrier associated with the particulardiscovery carrier via broadcast signaling (e.g., system information) orvia a serving cell in the serving eNB with dedicated signaling orbroadcast signaling. Thus, it is desirable to have coordination betweendifferent eNBs or PLMNs to allow the serving eNB to provide resourcepool configurations for transmitting and/or monitoring on other carriersthat do not belong to the serving eNB to which the UE is connected or onwhich the UE is camping.

In inter-carrier discovery, the serving eNB is allowed to providededicated or broadcasted reception/transmission (RX/TX) resource poolconfigurations for multiple carriers. As used herein, the RX/TX resourcepool is a term for one or more information elements in RRC togethercomprising a configuration that carries information about which resourceelements and subframes the UE monitors for incoming discovery messagesand uses to transmit outgoing discovery messages. It applies to aspecific carrier frequency with a certain bandwidth, and may alsocontain information such as the cyclic prefix length, the number ofretransmissions of each discovery message, the TDD-configuration (if TDDis used), and parameters related to synchronization. An example of theRX/TX resource pool is the information element SL-DiscResourcePool-r12described in 3GPP TS 36.331 v12.6.0.

As described above, in Release 12 the RX/TX resource pool configurationfor discovery carriers other than the PCell can be provided by theserving cell in which the UE is camping or connected, and by theparticular discovery carrier (in cases in which TDD is used) or by thepaired carrier associated with the particular discovery carrier (incases in which FDD is used). This can cause problems because the UEmight receive concurrent and different resource pool provisioning fromdifferent sources for RX/TX applicable to the same discovery carrier.Thus, a number of issues need to be addressed. For example, in somecases (e.g., when TDD is used) the UE might receive a first RX/TXresource pool configuration from the serving eNB and a second RX/TXresource pool configuration from system information on the particulardiscovery carrier in question. As another example, in some cases (e.g.,when FDD is used) the UE might receive a first RX/TX resource poolconfiguration from the serving eNB and a second RX/TX resource poolconfiguration from system information on the paired carrier associatedwith the particular discovery carrier.

How the different scenarios that may arise should be handled by the UEhas not yet been defined in the 3GPP standards. A standardized rule isneeded, however, in order to avoid UE misbehavior that could affectnetwork performance. For example, it has not been defined which resourcepool configuration the UE should prioritize for the particular discoverycarrier in question (e.g., the one received via the serving eNB or theone received from system information via either the particular discoverycarrier in question or the paired carrier associated with the particulardiscovery carrier, depending on whether TDD or FDD is used). Similarly,in a scenario where the UE receives the RX/TX resource poolconfiguration from the serving eNB, but no system information istransmitted on the particular discovery carrier in question (or thepaired carrier associated with the particular discovery carrier inquestion), it has not been defined whether the UE should interpret thisto mean the particular discovery carrier no longer supports ProSediscovery.

The present disclosure contemplates various embodiments that mayadvantageously prevent the UE misbehavior that could occur when the UEreceives concurrent and different resource pool provisioning fromdifferent sources for transmission and/or reception applicable to thesame discovery carrier.

In certain embodiments, the misbehavior that could occur when concurrentand different resource pool provisioning is received from differentsources is prevented by a method in a wireless device. According to oneexample embodiment, the wireless device receives one or more resourcepool configurations for a particular discovery carrier. The received oneor more resource pool configurations include at least a first resourcepool received from a serving network node of the wireless device. Theone or more resource pool configurations include information indicatingone or more resource elements and subframes that the wireless deviceshould use to monitor for incoming discovery messages and transmitoutgoing discovery messages. The wireless device determines which of thereceived one or more resource pool configurations that the wirelessdevice should use to monitor for incoming discovery messages andtransmit outgoing discovery messages.

In certain embodiments, the misbehavior that could occur when concurrentand different resource pool provisioning is received from differentsources is prevented by a method in a network node. The network nodedetermines a first resource pool configuration for a particulardiscovery carrier. The first resource pool configuration includesinformation indicating one or more of resource elements and subframesthat a wireless device should use to monitor for incoming discoverymessages and transmit outgoing discovery messages. The network nodecommunicates the first resource pool configuration to the wirelessdevice. The network node configures the wireless device to use one ofthe first resource pool configuration or a second resource poolconfiguration communicated via system information of the particulardiscovery carrier (when TDD is used) or the paired carrier associatedwith the particular discovery carrier (when FDD is used).

The various embodiments described herein may have one or more technicaladvantages. For example, certain embodiments may advantageously avoid UEmisbehavior when the UE receives concurrent and different resource poolprovisioning from different sources for transmission/receptionapplicable to the same discovery carriers. As another example, certainembodiments may reduce the amount of signaling that needs to be sentover the air, which may advantageously allow a UE to save batterybecause it does not need to continuously monitor system information fromthe particular discovery carrier. As still another example, the variousembodiments described herein may be implemented in both systems usingTDD and systems using FDD. Other advantages may be readily apparent toone having skill in the art. Certain embodiments may have none, some, orall of the recited advantages.

FIG. 1 is a block diagram illustrating an embodiment of a network 100,in accordance with certain embodiments. Network 100 includes one or moreUE(s) 110 (which may be interchangeably referred to as wireless devices110), and one or more network nodes 115 (which may be interchangeablyreferred to as eNBs 115). UEs 110 may communicate with network nodes 115over a wireless interface. For example, UE 110A may transmit wirelesssignals to one or more of network nodes 115, and/or receive wirelesssignals from one or more of network nodes 115. The wireless signals maycontain voice traffic, data traffic, control signals, and/or any othersuitable information. UEs 110 and network nodes 115 may be capable ofoperating using TDD, FDD, or any other suitable mode of operation. Insome embodiments, an area of wireless signal coverage associated with anetwork node 115 may be referred to as a cell. In some embodiments, UEs110 may have D2D capability. Thus, UEs 110 may be able to receivesignals from and/or transmit signals directly to another UE. Forexample, UE 110A may be able to receive signals from and/or transmitsignals to UE 110D.

In certain embodiments, network nodes 115 may interface with a radionetwork controller. The radio network controller may control networknodes 115 and may provide certain radio resource management functions,mobility management functions, and/or other suitable functions. Incertain embodiments, the functions of the radio network controller maybe performed by network node 115. The radio network controller mayinterface with a core network node. In certain embodiments, the radionetwork controller may interface with the core network node via aninterconnecting network. The interconnecting network may refer to anyinterconnecting system capable of transmitting audio, video, signals,data, messages, or any combination of the preceding. The interconnectingnetwork may include all or a portion of a public switched telephonenetwork (PSTN), a public or private data network, a local area network(LAN), a metropolitan area network (MAN), a wide area network (WAN), alocal, regional, or global communication or computer network such as theInternet, a wireline or wireless network, an enterprise intranet, or anyother suitable communication link, including combinations thereof.

In some embodiments, the core network node may manage the establishmentof communication sessions and various other functionalities for UEs 110.UEs 110 may exchange certain signals with the core network node usingthe non-access stratum (NAS) layer. In non-access stratum signaling,signals between UEs 110 and the core network node may be transparentlypassed through the radio access network. In certain embodiments, networknodes 115 may interface with one or more network nodes over an internodeinterface. For example, network nodes 115A and 115B may interface overan X2 interface.

As described above, example embodiments of network 100 may include oneor more UEs 110, and one or more different types of network nodescapable of communicating (directly or indirectly) with UEs 110.

In some embodiments, the non-limiting term UE is used. UEs 110 describedherein can be any type of wireless device capable of communicating withnetwork nodes 115 or another UE over radio signals. UE 110 may be aradio communication device, target device, D2D UE,machine-type-communication (MTC) UE or UE capable of machine-to-machinecommunication (M2M), low-cost and/or low-complexity UE, a sensorequipped with UE, Tablet, mobile terminals, smart phone, laptop embeddedequipped (LEE), laptop mounted equipment (LME), USB dongles, CustomerPremises Equipment (CPE), etc. UE 110 may operate under either normalcoverage or enhanced coverage with respect to its serving cell. Theenhanced coverage may be interchangeably referred to as extendedcoverage. UE 110 may also operate in a plurality of coverage levels(e.g., normal coverage, enhanced coverage level 1, enhanced coveragelevel 2, enhanced coverage level 3 and so on). In some cases, UE 110 mayalso operate in out-of-coverage scenarios.

Also, in some embodiments generic terminology, “radio network node” (orsimply “network node”) is used. It can be any kind of network node,which may comprise a base station (BS), radio base station, Node B, basestation (BS), multi-standard radio (MSR) radio node such as MSR BS,evolved Node B (eNB), network controller, radio network controller(RNC), base station controller (BSC), relay node, relay donor nodecontrolling relay, base transceiver station (BTS), access point (AP),radio access point, transmission points, transmission nodes, RemoteRadio Unit (RRU), Remote Radio Head (RRH), nodes in distributed antennasystem (DAS), Multi-cell/multicast Coordination Entity (MCE), corenetwork node (e.g., MSC, MME, etc.), O&M, OSS, SON, positioning node(e.g., E-SMLC), MDT, translation node (e.g., PLAT) or any other suitablenetwork node.

The terminology such as network node and UE should be considerednon-limiting and does in particular not imply a certain hierarchicalrelation between the two; in general “eNodeB” could be considered asdevice 1 and “UE” device 2, and these two devices communicate with eachother over some radio channel.

Example embodiments of UE 110, network nodes 115, and other networknodes (such as radio network controller or core network node) aredescribed in more detail below with respect to FIGS. 6-10.

Although FIG. 1 illustrates a particular arrangement of network 100, thepresent disclosure contemplates that the various embodiments describedherein may be applied to a variety of networks having any suitableconfiguration. For example, network 100 may include any suitable numberof UEs 110 and network nodes 115, as well as any additional elementssuitable to support communication between UEs or between a UE andanother communication device (such as a landline telephone).Furthermore, although certain embodiments may be described asimplemented in a Long Term Evolution (LTE) network, the embodiments maybe implemented in any appropriate type of telecommunication systemsupporting any suitable communication standards (including 5G standards)and using any suitable components, and are applicable to any radioaccess technology (RAT) or multi-RAT systems in which a UE receivesand/or transmits signals (e.g., data). For example, the variousembodiments described herein may be applicable to LTE, LTE-Advanced, 5G,UMTS, HSPA, GSM, cdma2000, WCDMA, WiMax, UMB, WiFi, another suitableradio access technology, or any suitable combination of one or moreradio access technologies. Although certain embodiments may be describedin the context of wireless transmissions in the downlink, the presentdisclosure contemplates that the various embodiments are equallyapplicable in the uplink.

As described above, a UE, such as UE 110A in FIG. 1, may receive one ormore RX/TX resource pool configurations for a particular discoverycarrier (which may be interchangeably referred to herein as a“particular ProSe discovery carrier”) from different sources. As oneexample, in cases where UE 110A uses TDD, the resource poolconfiguration for a particular discovery carrier may be provided to UE110A from one or more of the serving cell in which the UE is camping orconnected (e.g., network node 115A) and the particular discovery carrieritself (e.g., via system information).

As another example, in cases where UE 110A is using FDD, the resourcepool configuration for a particular discovery carrier may be provided toUE 110A from one or more of the serving cell in which UE 110A is campingon or connected (e.g., network node 115A) and by a paired carrierassociated with the particular discovery carrier (e.g., via systeminformation). To illustrate, consider the following example scenario. InFDD mode, UE 110A can receive a first resource pool configuration fromits serving network node, such as network node 115A. Serving networknode 115A is responsible for FDD carrier F1, which consists of carriersF1d and F1u (“d” for downlink, “u” for uplink). Serving network node115A transmits system information on carrier F1d which indicates whichresources to use on a second carrier, F2u. In this example, F2u is theparticular discovery carrier on which UE 110A monitors for incomingdiscovery messages and transmits outgoing discovery messages. F2u (andits paired carrier, F2d) are handled by another non-serving networknode, such as network node 115B in FIG. 1. Network node 115B broadcastsits system information on the paired carrier (i.e., F2d) associated withthe particular discovery carrier (i.e., F2u). The system informationbroadcasted on paired carrier F2d indicates which resources to use onthe particular discovery carrier F2u. Thus, UE 110A operating in FDDmode can receive a first resource pool configuration for the particulardiscovery carrier (i.e., F2u in this example) from serving network node115A (via carrier F1d), and a second resource pool configuration for theparticular discovery carrier (i.e., F2u) from non-serving network node115B (e.g., via system information on the paired carrier associated withthe particular discovery carrier).

This can cause problems because UE 110A might receive concurrent anddifferent resource pool provisioning from different sources for RX/TXapplicable to the same discovery carrier. In certain embodiments, theproblems that can occur when UE 110A receives concurrent and differentresource pool configurations from different sources for transmissionand/or reception may be prevented by configuring UE 110A to use aparticular resource pool configuration in a particular scenario.Examples of how a network node, such as network node 115A, can configureUE 110A to use a particular resource pool configuration in a particularscenario are described in more detail below with respect to FIGS. 3 and5. UE 110A can then determine which of the received one or more resourcepool configurations UE 110A should use to monitor for incoming discoverymessages and transmit outgoing discovery messages.

As used herein, system information refers generally to any signalingsuitable to convey a resource pool configuration for a particulardiscovery carrier to a UE. For example, in certain embodiments thesystem information may be SIB19. Although the various embodiments may bedescribed using SIB19 as an example of the system information, thepresent disclosure contemplates that the system information used toconvey a resource pool configuration for a particular discovery carrierto a UE may vary according to particular limitations, and the systeminformation described herein is not limited to SIB19.

Furthermore, although certain embodiments are described using particularexamples involving UE 110A, serving network node 115A, and non-servingnetwork node 115B, the various embodiments described herein are notlimited to such an example arrangement.

According to one example embodiment, UE 110A receives one or moreresource pool configurations for a particular discovery carrier. Thereceived one or more resource pool configurations include at least afirst resource pool configuration received from serving network node115A of UE 110A. In some cases, such as when UE 110A uses TDD, UE 110Adetermines whether the received one or more resource pool configurationsinclude a second resource pool configuration received via systeminformation (e.g., SIB19) of the particular discovery carrier. In somecases, such as when UE 110A uses FDD, UE 110A determines whether thereceived one or more resource pool configurations for the particulardiscovery carrier includes a second resource pool configuration receivedvia system information (e.g., SIB19) of a paired carrier associated withthe particular discovery carrier.

In either case, UE 110A may determine that it has received a secondresource pool configuration (either via system information of theparticular discovery carrier, or via system information of the pairedcarrier associated with the particular discovery carrier, depending onwhether UE 110A uses TDD or FDD, respectively). This may occur becausenetwork node 115A (to which UE 110A is connected or camping on) mighthave bad coordination with the particular discovery carrier that may bemanaged by non-serving network node 1158 in the same PLMN or anothernetwork node 115 in another PLMN. The bad coordination might be due to avariety of factors, such as one or more of unreliability, misbehavior,and speed of the coordination interface (e.g., the X2 or S1 interface).

Upon determining that the received one or more resource poolconfigurations for the particular discovery carrier includes the secondresource pool configuration, UE 110A uses the second resource poolconfiguration to monitor for incoming discovery messages and transmitoutgoing discovery messages. Thus, UE 110A uses the second resource poolconfiguration to monitor for incoming discovery messages and transmitoutgoing discovery messages instead of the first resource poolconfiguration provided for the particular discovery carrier in questionby the serving cell (i.e., network node 115A) via broadcast or dedicatedsignaling.

According to another example embodiment, UE 110A receives one or moreresource pool configurations for the particular discovery carrier. Thereceived one or more resource pool configurations include at least afirst resource pool configuration received from serving network node115A of UE 110A. In cases where UE 110A uses TDD, UE 110A determineswhether the particular discovery carrier contains system information. Incases where UE 110A uses FDD, UE 110A determines whether the pairedcarrier associated with the particular discovery carrier contains systeminformation. UE 110A may determine that the particular discovery carrierin which UE 110A would like to transmit discovery messages does notcontain system information (in cases where TDD is used), or maydetermine that the paired carrier associated with the particulardiscovery carrier does not contain system information (in cases whereFDD is used). This may, for example, be due to the fact that theparticular discovery carrier no longer supports ProSe discovery. Upondetermining that the particular discovery carrier (or the paired carrierassociated with the particular discovery carrier, depending on the modeof operation used) does not contain system information, UE 110Adetermines whether UE 110A is located at a cell edge between in-coverageand out-of-coverage for the particular discovery carrier.

Upon determining that UE 110A is not located at a cell edge betweenin-coverage and out-of-coverage for the particular discovery carrier, UE110A determines that the first resource pool configuration received fromserving network node 115A of UE 110A should not be used to monitor forincoming discovery messages and transmit outgoing discovery messages.Therefore, UE 110A does not use the resource pool configuration providedby the serving cell, and no ProSe Discovery is performed on theparticular discovery carrier. This is referred to herein as behavior A.

In another scenario, however, UE 110A may not receive system informationbecause UE 110A is located on the cell edge between in-coverage andout-of-coverage for that particular discovery carrier. In such a case,UE 110A might not be able to read system information from thatparticular ProSe discovery carrier for a short period of time. Upondetermining that UE 110A is located at a cell edge between in-coverageand out-of-coverage for the particular discovery carrier, UE 110A usesthe first resource pool configuration received from serving network node115A of UE 110A to monitor for incoming discovery messages and transmitoutgoing discovery messages. Thus, in this scenario, UE 110A uses thefirst resource pool configuration provided by serving network node 115A.This is referred to herein as behavior B.

The present disclosure contemplates that UE 110A may switch frombehavior A to behavior B in any suitable manner. The determination ofwhether UE 110A is located at the cell edge between in-coverage andout-of-coverage for the particular discovery carrier, and thus thetransition between behavior A and behavior B, may be based on anysuitable criteria. For example, determining whether UE 110A is locatedat the cell edge between in-coverage and out-of-coverage for theparticular discovery carrier may be based on whether system informationis not received by UE 110A for a particular duration. In certainembodiments, switching between behavior A and B may be based on a timer.As one example, a timer can be configured by the network orpreconfigured by UE 110A such that if system information is not read fora certain period, UE 110A can continue to use the resources provided byserving network node 115A to which UE 110A is still connected (i.e.,behavior B).

In certain embodiments, determining whether UE 110A is located at thecell edge between in-coverage and out-of-coverage for the particulardiscovery carrier may be based on whether an S-criterion is notfulfilled for a second duration. The S-criterion, which is defined in3GPP TS 36.304 v12.5.0 section 5.2.3.2, is used to determine when UE110A is out-of-coverage or in-coverage with respect to the particulardiscovery carrier. For example, in switching between behavior A and B UE110A may apply a timer to the S-criterion. If the S-criterion has notbeen fulfilled for a certain time, the particular discovery carrier isdeclared out-of-coverage and UE 110A switches from behavior B to A(i.e., UE 110A does not use the first resource pool configurationprovided by serving network node 115). Otherwise, before the timerexpires UE 110A follows behavior B (even though the system informationfrom the particular discovery carrier cannot be detected).

According to another example embodiment, UE 110A receives one or moreresource pool configurations for a particular discovery carrier. Thereceived one or more resource pool configurations include at least afirst resource pool configuration received from serving network node115A of UE 110A. In cases where TDD is used, UE 110A determines whethersystem information of the particular discovery carrier is broadcast atall. In cases where FDD is used, UE 110A determines whether systeminformation of the paired carrier associated with the particulardiscovery carrier is broadcast at all.

In cases where TDD is used, UE 110A may determine that the particularProSe discovery carrier supports ProSe discovery, but no systeminformation is broadcasted. In cases where FDD is used, UE 110A maydetermine that the particular ProSe discovery carrier supports ProSediscovery, but no system information of the paired carrier associatedwith the particular discovery carrier is broadcast. Upon determiningthat system information of the particular discovery carrier is notbroadcast (or that system information of the paired carrier associatedwith the particular discovery carrier is not broadcast, depending onwhether UE 110A uses TDD or FDD), UE 110A uses the first resource poolconfiguration received from serving network node 115A of UE 110A tomonitor for incoming discovery messages and transmit outgoing discoverymessages. Thus, in this scenario the serving cell provides the necessaryresource pool configuration for transmission on the particular ProSediscovery carrier in question. Configuring the system in this manner canbe useful for network performance because no signaling needs to be sentover the air, and UE 110A can save battery because it does not need tocontinuously monitor system information (e.g., SIB19) from theparticular ProSe discovery carrier (or from the paired carrierassociated with the particular ProSe discovery carrier, depending onwhether TDD or FDD is used.

In such a scenario, UE 110A may not know if the system information fromthe particular ProSe discovery carrier is not broadcasted because ofreasons related to the system configuration or due to misdetection. Incertain embodiments, UE 110A receives an indication from serving networknode 115A that the particular discovery carrier does not support systeminformation (or receives an indication from serving network node 115Athat the paired carrier associated with the particular discovery carrierdoes not support system information, depending on whether TDD or FDD isused). For example, the serving cell may signal as part of the dedicatedand/or broadcast signaling that the particular ProSe discovery carrier(or the paired carrier associated with the particular discovery carrierin FDD mode) does not support system information (e.g., SIB19).Otherwise, UE 110A can understand that no signaling is provided by theparticular ProSe discovery carrier (or the paired carrier associatedwith the particular ProSe discovery carrier) if no system information isreceived for some consecutive number of decoding attempts.

In certain embodiments, upon determining that system information of theparticular discovery carrier (or that system information of the pairedcarrier associated with the particular discovery carrier) is broadcast,UE 110A determines whether the system information of the particulardiscovery carrier (or the system information of the paired carrierassociated with the particular discovery carrier) includes a secondresource pool configuration. For example, for a system operating usingTDD, the particular ProSe discovery carrier may broadcast systeminformation, but the second resource pool configuration may not beincluded. Similarly, for a system operating using FDD, the pairedcarrier associated with the particular discovery carrier may broadcastsystem information, but the second resource pool configuration may notbe included. This can be done to limit the overhead of signaling. Upondetermining that the system information of the particular discoverycarrier (or the paired carrier associated with the particular discoverycarrier when FDD mode is used) does not include the second resource poolconfiguration, UE 110A uses the first resource pool configurationreceived from serving network node 115A of UE 110A to monitor forincoming discovery messages and transmit outgoing discovery messages.

There might be cases in which system information (e.g., SIB19) or itscontent cannot be read because of misdetection. Therefore servingnetwork node 115A can also signal as part of the dedicated and/orbroadcast signaling that the particular ProSe discovery carrier does notprovide resources for direct discovery transmission/reception.Otherwise, UE 110A can understand that no resources are provided by theparticular ProSe discovery carrier if no resource pool configuration isincluded in system information for some consecutive number of decodingattempts.

FIG. 2 is a flow diagram of a method 200 in a wireless device, inaccordance with certain embodiments. The method begins at step 204,where the wireless device receives one or more resource poolconfigurations for a particular discovery carrier, the one or moreresource pool configurations comprising information indicating one ormore of resource elements and subframes that the wireless device shoulduse to monitor for incoming discovery messages and transmit outgoingdiscovery messages, the received one or more resource poolconfigurations comprising at least a first resource pool configurationreceived from a serving network node of the wireless device operating inTime Division Duplex (TDD) mode.

At step 208, the wireless device determines which of the received one ormore resource pool configurations that the wireless device should use tomonitor for incoming discovery messages and transmit outgoing discoverymessages.

In certain embodiments, the method may comprise determining whether thereceived one or more resource pool configurations for the particulardiscovery carrier include a second resource pool configuration receivedvia system information of the particular discovery carrier. In certainembodiments, the system information may comprise a session informationblock 19. In some cases, upon determining that the received one or moreresource pool configurations for the particular discovery carrierincludes the second resource pool configuration received via systeminformation of the particular discovery carrier, the wireless deviceuses the second resource pool configuration to monitor for incomingdiscovery messages and transmit outgoing discovery messages.

In certain embodiments, the method may comprise determining whether theparticular discovery carrier contains system information. Upondetermining that the particular discovery carrier does not containsystem information, the wireless device may determine whether thewireless device is located at a cell edge between in-coverage andout-of-coverage for the particular discovery carrier. In some cases,upon determining that the wireless device is not located at a cell edgebetween in-coverage and out-of-coverage for the particular discoverycarrier, the wireless device determines that the first resource poolconfiguration received from the serving network node of the wirelessdevice should not be used to monitor for incoming discovery messages andtransmit outgoing discovery messages. In some cases, upon determiningthat the wireless device is located at a cell edge between in-coverageand out-of-coverage for the particular discovery carrier, the wirelessdevice uses the first resource pool configuration received from theserving network node of the wireless device to monitor for incomingdiscovery messages and transmit outgoing discovery messages. In certainembodiments, determining whether the wireless device is located at thecell edge between in-coverage and out-of-coverage for the particulardiscovery carrier may be based on at least one of: whether systeminformation is not received by the wireless device for a first duration;and whether an S-criterion used to determine when the wireless device isout-of-coverage or in-coverage with respect to the particular discoverycarrier is not fulfilled for a second duration.

In certain embodiments, the method may comprise determining whethersystem information of the particular discovery carrier is broadcast. Insome cases, upon determining that system information of the particulardiscovery carrier is not broadcast, the wireless device uses the firstresource pool configuration received from the serving network node ofthe wireless device to monitor for incoming discovery messages andtransmit outgoing discovery messages. In certain embodiments, the methodmay comprise receiving an indication from the serving network node thatthe particular discovery carrier does not support system information. Insome cases, upon determining that system information of the particulardiscovery carrier is broadcast, the wireless device determines whetherthe system information of the particular discovery carrier includes asecond resource pool configuration. In some cases, upon determining thatthe system information of the particular discovery carrier does notinclude the second resource pool configuration, the wireless device usesthe first resource pool configuration received from the serving networknode of the wireless device to monitor for incoming discovery messagesand transmit outgoing discovery messages.

FIG. 3 is a flow diagram of a method 300 in a network node, inaccordance with certain embodiments. The method begins at step 304,where the network node determines a first resource pool configurationfor a particular discovery carrier, the first resource poolconfiguration comprising information indicating one or more of resourceelements and subframes that a wireless device operating in Time DivisionDuplex (TDD) mode should use to monitor for incoming discovery messagesand transmit outgoing discovery messages.

At step 308, the network node communicates the first resource poolconfiguration to the wireless device.

At step 312, the network node configures the wireless device to use oneof the first resource pool configuration or a second resource poolconfiguration communicated via system information of the particulardiscovery carrier. In certain embodiments, the system information maycomprise a session information block 19.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thesecond resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the wireless devicereceives both the first resource pool configuration and the secondresource pool configuration.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to not usethe first resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the particulardiscovery carrier does not contain system information and the wirelessdevice is not located at a cell edge between in-coverage andout-of-coverage for the particular discovery carrier.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the particulardiscovery carrier does not contain system information and the wirelessdevice is located at a cell edge between in-coverage and out-of-coveragefor the particular discovery carrier.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if system informationof the particular discovery carrier is not broadcast. In certainembodiments, the method may comprise communicating an indication to thewireless device that the particular discovery carrier does not supportsystem information.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the systeminformation of the particular discovery carrier is broadcast but doesnot include the second resource pool configuration.

FIG. 4 is a flow diagram of a method 400 in a wireless device, inaccordance with certain embodiments. The method begins at step 404,where the wireless device receives one or more resource poolconfigurations for a particular discovery carrier, the one or moreresource pool configurations comprising information indicating one ormore of resource elements and subframes that the wireless device shoulduse to monitor for incoming discovery messages and transmit outgoingdiscovery messages, the received one or more resource poolconfigurations comprising at least a first resource pool configurationreceived from a serving network node of the wireless device operating inFrequency Division Duplex Mode (FDD) mode.

At step 408, the wireless device determines which of the received one ormore resource pool configurations that the wireless device should use tomonitor for incoming discovery messages and transmit outgoing discoverymessages.

In certain embodiments, the method may comprise determining whether thereceived one or more resource pool configurations for the particulardiscovery carrier includes a second resource pool configuration receivedvia system information of a paired carrier associated with theparticular discovery carrier. In certain embodiments, the systeminformation may comprise a session information block 19. In some cases,upon determining that the received one or more resource poolconfigurations for the particular discovery carrier includes the secondresource pool configuration received via system information of thepaired carrier associated with the particular discovery carrier, thewireless device uses the second resource pool configuration to monitorfor incoming discovery messages and transmit outgoing discoverymessages.

In certain embodiments, the method may comprise determining whether thepaired carrier associated with the particular discovery carrier containssystem information. Upon determining that the paired carrier associatedwith the particular discovery carrier does not contain systeminformation, the wireless device may determine whether the wirelessdevice is located at a cell edge between in-coverage and out-of-coveragefor the particular discovery carrier. In some cases, upon determiningthat the wireless device is not located at a cell edge betweenin-coverage and out-of-coverage for the particular discovery carrier,the wireless device determines that the first resource poolconfiguration received from the serving network node of the wirelessdevice should not be used to monitor for incoming discovery messages andtransmit outgoing discovery messages. In some cases, upon determiningthat the wireless device is located at a cell edge between in-coverageand out-of-coverage for the particular discovery carrier, the wirelessdevice uses the first resource pool configuration received from theserving network node of the wireless device to monitor for incomingdiscovery messages and transmit outgoing discovery messages. In certainembodiments, determining whether the wireless device is located at thecell edge between in-coverage and out-of-coverage for the particulardiscovery carrier may be based on at least one of: whether systeminformation is not received by the wireless device for a first duration;and whether an S-criterion used to determine when the wireless device isout-of-coverage or in-coverage with respect to the particular discoverycarrier is not fulfilled for a second duration.

In certain embodiments, the method may comprise determining whethersystem information of a paired carrier associated with the particulardiscovery carrier is broadcast. In some cases, upon determining thatsystem information of the paired carrier associated with the particulardiscovery carrier is not broadcast, the wireless device uses the firstresource pool configuration received from the serving network node ofthe wireless device to monitor for incoming discovery messages andtransmit outgoing discovery messages. In certain embodiments, the methodmay comprise receiving an indication from the serving network node thatthe paired carrier associated with the particular discovery carrier doesnot support system information. In some cases, upon determining thatsystem information of the paired carrier associated with the particulardiscovery carrier is broadcast, the wireless device determines whetherthe system information of the paired carrier associated with theparticular discovery carrier includes a second resource poolconfiguration. In some cases, upon determining that the systeminformation of the paired carrier associated with the particulardiscovery carrier does not include the second resource poolconfiguration, the wireless device uses the first resource poolconfiguration received from the serving network node of the wirelessdevice to monitor for incoming discovery messages and transmit outgoingdiscovery messages.

FIG. 5 is a flow diagram of a method 500 in a network node, inaccordance with certain embodiments. The method begins at step 504,where the network node determines a first resource pool configurationfor a particular discovery carrier, the first resource poolconfiguration comprising information indicating one or more of resourceelements and subframes that a wireless device operating in FrequencyDivision Duplex (FDD) mode should use to monitor for incoming discoverymessages and transmit outgoing discovery messages.

At step 508, the network node communicates the first resource poolconfiguration to the wireless device.

At step 512, the network node configures the wireless device to use oneof the first resource pool configuration or a second resource poolconfiguration communicated via system information of a paired carrierassociated with the particular discovery carrier. In certainembodiments, the system information may comprise a session informationblock 19.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thesecond resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the wireless devicereceives both the first resource pool configuration and the secondresource pool configuration.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to not usethe first resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the paired carrierassociated with the particular discovery carrier does not contain systeminformation and the wireless device is not located at a cell edgebetween in-coverage and out-of-coverage for the particular discoverycarrier.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the paired carrierassociated with the particular discovery carrier does not contain systeminformation and the wireless device is located at a cell edge betweenin-coverage and out-of-coverage for the particular discovery carrier.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if system informationof the paired carrier associated with the particular discovery carrieris not broadcast. In certain embodiments, the method may comprisecommunicating an indication to the wireless device that the pairedcarrier associated with the particular discovery carrier does notsupport system information.

In certain embodiments, configuring the wireless device to use one ofthe first resource pool configuration or the second resource poolconfiguration may comprise configuring the wireless device to use thefirst resource pool configuration to monitor for incoming discoverymessages and transmit outgoing discovery messages if the systeminformation of the paired carrier associated with the particulardiscovery carrier is broadcast but does not include the second resourcepool configuration.

FIG. 6 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments. Wireless device 110 may refer toany type of wireless device communicating with a node and/or withanother wireless device in a cellular or mobile communication system.Examples of wireless device 110 include a mobile phone, a smart phone, aPDA (Personal Digital Assistant), a portable computer (e.g., laptop,tablet), a sensor, a modem, a machine-type-communication (MTC)device/machine-to-machine (M2M) device, laptop embedded equipment (LEE),laptop mounted equipment (LME), USB dongles, a D2D capable device, oranother device that can provide wireless communication. A wirelessdevice 110 may also be referred to as UE, a station (STA), a device, ora terminal in some embodiments. Wireless device 110 includes transceiver610, processor 620, and memory 630. In some embodiments, transceiver 610facilitates transmitting wireless signals to and receiving wirelesssignals from network node 115 (e.g., via antenna 640), processor 620executes instructions to provide some or all of the functionalitydescribed above as being provided by wireless device 110, and memory 630stores the instructions executed by processor 620.

Processor 620 may include any suitable combination of hardware andsoftware implemented in one or more modules to execute instructions andmanipulate data to perform some or all of the described functions ofwireless device 110, such as the functions of wireless device 110described above in relation to FIGS. 1-5. In some embodiments, processor620 may include, for example, one or more computers, one or more centralprocessing units (CPUs), one or more microprocessors, one or moreapplications, one or more application specific integrated circuits(ASICs), one or more field programmable gate arrays (FPGAs) and/or otherlogic.

Memory 630 is generally operable to store instructions, such as acomputer program, software, an application including one or more oflogic, rules, algorithms, code, tables, etc. and/or other instructionscapable of being executed by a processor. Examples of memory 630 includecomputer memory (for example, Random Access Memory (RAM) or Read OnlyMemory (ROM)), mass storage media (for example, a hard disk), removablestorage media (for example, a Compact Disk (CD) or a Digital Video Disk(DVD)), and/or or any other volatile or non-volatile, non-transitorycomputer-readable and/or computer-executable memory devices that storeinformation, data, and/or instructions that may be used by processor620.

Other embodiments of wireless device 110 may include additionalcomponents beyond those shown in FIG. 6 that may be responsible forproviding certain aspects of the wireless device's functionality,including any of the functionality described above and/or any additionalfunctionality (including any functionality necessary to support thesolution described above). As just one example, wireless device 110 mayinclude input devices and circuits, output devices, and one or moresynchronization units or circuits, which may be part of the processor620. Input devices include mechanisms for entry of data into wirelessdevice 110. For example, input devices may include input mechanisms,such as a microphone, input elements, a display, etc. Output devices mayinclude mechanisms for outputting data in audio, video and/or hard copyformat. For example, output devices may include a speaker, a display,etc.

FIG. 7 is a block schematic of an exemplary network node, in accordancewith certain embodiments. Network node 115 may be any type of radionetwork node or any network node that communicates with a UE and/or withanother network node. Examples of network node 115 include an eNodeB, anode B, a base station, a wireless access point (e.g., a Wi-Fi accesspoint), a low power node, a base transceiver station (BTS), relay, donornode controlling relay, transmission points, transmission nodes, remoteRF unit (RRU), remote radio head (RRH), multi-standard radio (MSR) radionode such as MSR BS, nodes in distributed antenna system (DAS), O&M,OSS, SON, positioning node (e.g., E-SMLC), MDT, or any other suitablenetwork node. Network nodes 115 may be deployed throughout network 100as a homogenous deployment, heterogeneous deployment, or mixeddeployment. A homogeneous deployment may generally describe a deploymentmade up of the same (or similar) type of network nodes 115 and/orsimilar coverage and cell sizes and inter-site distances. Aheterogeneous deployment may generally describe deployments using avariety of types of network nodes 115 having different cell sizes,transmit powers, capacities, and inter-site distances. For example, aheterogeneous deployment may include a plurality of low-power nodesplaced throughout a macro-cell layout. Mixed deployments may include amix of homogenous portions and heterogeneous portions.

Network node 115 may include one or more of transceiver 710, processor720, memory 730, and network interface 740. In some embodiments,transceiver 710 facilitates transmitting wireless signals to andreceiving wireless signals from wireless device 110 (e.g., via antenna750), processor 720 executes instructions to provide some or all of thefunctionality described above as being provided by a network node 115,memory 730 stores the instructions executed by processor 720, andnetwork interface 740 communicates signals to backend networkcomponents, such as a gateway, switch, router, Internet, Public SwitchedTelephone Network (PSTN), core network nodes or radio networkcontrollers 130, etc.

Processor 720 may include any suitable combination of hardware andsoftware implemented in one or more modules to execute instructions andmanipulate data to perform some or all of the described functions ofnetwork node 115, such as those described above in relation to FIGS. 1-5above. In some embodiments, processor 720 may include, for example, oneor more computers, one or more central processing units (CPUs), one ormore microprocessors, one or more applications, and/or other logic.

Memory 730 is generally operable to store instructions, such as acomputer program, software, an application including one or more oflogic, rules, algorithms, code, tables, etc. and/or other instructionscapable of being executed by a processor. Examples of memory 730 includecomputer memory (for example, Random Access Memory (RAM) or Read OnlyMemory (ROM)), mass storage media (for example, a hard disk), removablestorage media (for example, a Compact Disk (CD) or a Digital Video Disk(DVD)), and/or or any other volatile or non-volatile, non-transitorycomputer-readable and/or computer-executable memory devices that storeinformation.

In some embodiments, network interface 740 is communicatively coupled toprocessor 720 and may refer to any suitable device operable to receiveinput for network node 115, send output from network node 115, performsuitable processing of the input or output or both, communicate to otherdevices, or any combination of the preceding. Network interface 740 mayinclude appropriate hardware (e.g., port, modem, network interface card,etc.) and software, including protocol conversion and data processingcapabilities, to communicate through a network.

Other embodiments of network node 115 may include additional componentsbeyond those shown in FIG. 7 that may be responsible for providingcertain aspects of the radio network node's functionality, including anyof the functionality described above and/or any additional functionality(including any functionality necessary to support the solutionsdescribed above). The various different types of network nodes mayinclude components having the same physical hardware but configured(e.g., via programming) to support different radio access technologies,or may represent partly or entirely different physical components.

FIG. 8 is a block schematic of an exemplary radio network controller orcore network node 130, in accordance with certain embodiments. Examplesof network nodes can include a mobile switching center (MSC), a servingGPRS support node (SGSN), a mobility management entity (MME), a radionetwork controller (RNC), a base station controller (BSC), and so on.The radio network controller or core network node 130 includes processor820, memory 830, and network interface 840. In some embodiments,processor 820 executes instructions to provide some or all of thefunctionality described above as being provided by the network node,memory 830 stores the instructions executed by processor 820, andnetwork interface 840 communicates signals to any suitable node, such asa gateway, switch, router, Internet, Public Switched Telephone Network(PSTN), network nodes 115, radio network controllers or core networknodes 130, etc.

Processor 820 may include any suitable combination of hardware andsoftware implemented in one or more modules to execute instructions andmanipulate data to perform some or all of the described functions of theradio network controller or core network node 130. In some embodiments,processor 820 may include, for example, one or more computers, one ormore central processing units (CPUs), one or more microprocessors, oneor more applications, and/or other logic.

Memory 830 is generally operable to store instructions, such as acomputer program, software, an application including one or more oflogic, rules, algorithms, code, tables, etc. and/or other instructionscapable of being executed by a processor. Examples of memory 830 includecomputer memory (for example, Random Access Memory (RAM) or Read OnlyMemory (ROM)), mass storage media (for example, a hard disk), removablestorage media (for example, a Compact Disk (CD) or a Digital Video Disk(DVD)), and/or or any other volatile or non-volatile, non-transitorycomputer-readable and/or computer-executable memory devices that storeinformation.

In some embodiments, network interface 840 is communicatively coupled toprocessor 820 and may refer to any suitable device operable to receiveinput for the network node, send output from the network node, performsuitable processing of the input or output or both, communicate to otherdevices, or any combination of the preceding. Network interface 840 mayinclude appropriate hardware (e.g., port, modem, network interface card,etc.) and software, including protocol conversion and data processingcapabilities, to communicate through a network.

Other embodiments of the network node may include additional componentsbeyond those shown in FIG. 8 that may be responsible for providingcertain aspects of the network node's functionality, including any ofthe functionality described above and/or any additional functionality(including any functionality necessary to support the solution describedabove).

FIG. 9 is a block schematic of an exemplary wireless device, inaccordance with certain embodiments. Wireless device 110 may include oneor more modules. For example, wireless device 110 may include adetermining module 910, a communication module 920, a receiving module930, an input module 940, a display module 950, and any other suitablemodules. Wireless device 110 may perform the methods for provisioningtransmission pools for inter-carrier ProSe direct discovery describedabove with respect to FIGS. 1-5.

Determining module 910 may perform the processing functions of wirelessdevice 110. For example, in certain embodiments wireless device 110 mayuse TDD. In such a case, determining module 910 may determine which ofthe received one or more resource pool configurations that wirelessdevice 110 should use to monitor for incoming discovery messages andtransmit outgoing discovery messages. As another example, determiningmodule 910 may determine whether the received one or more resource poolconfigurations for the particular discovery carrier include a secondresource pool configuration received via system information of theparticular discovery carrier. As another example, determining module 910may determine whether the particular discovery carrier contains systeminformation. As still another example, determining module 910 maydetermine whether system information of the particular discovery carrieris broadcast. As yet another example, determining module 910 maydetermine whether the system information of the particular discoverycarrier includes a second resource pool configuration.

In certain embodiments, wireless device 110 may use FDD. In such a case,determining module 910 may determine which of the received one or moreresource pool configurations that wireless device 110 should use tomonitor for incoming discovery messages and transmit outgoing discoverymessages. As another example, determining module 910 may determinewhether the received one or more resource pool configurations for theparticular discovery carrier include a second resource poolconfiguration received via system information of a paired carrierassociated with the particular discovery carrier. As another example,determining module 910 may determine whether the paired carrierassociated with the particular discovery carrier contains systeminformation. As still another example, determining module 910 maydetermine whether system information of the paired carrier associatedwith the particular discovery carrier is broadcast. As yet anotherexample, determining module 910 may determine whether the systeminformation of the paired carrier associated with the particulardiscovery carrier includes a second resource pool configuration.

Determining module 910 may include or be included in one or moreprocessors, such as processor 620 described above in relation to FIG. 6.Determining module 910 may include analog and/or digital circuitryconfigured to perform any of the functions of determining module 910and/or processor 620 described above. The functions of determiningmodule 910 described above may, in certain embodiments, be performed inone or more distinct modules.

Communication module 920 may perform the transmission functions ofwireless device 110. Communication module 920 may transmit messages toone or more of network nodes 115 of network 100. Communication module920 may include a transmitter and/or a transceiver, such as transceiver610 described above in relation to FIG. 6. Communication module 920 mayinclude circuitry configured to wirelessly transmit messages and/orsignals. In particular embodiments, communication module 920 may receivemessages and/or signals for transmission from determining module 910. Incertain embodiments, the functions of communication module 920 describedabove may be performed in one or more distinct modules.

Receiving module 930 may perform the receiving functions of wirelessdevice 110. In certain embodiments, wireless device 110 may use TDD. Insuch a case, receiving module 930 may receive one or more resource poolconfigurations for a particular discovery carrier, the one or moreresource pool configurations comprising information indicating one ormore of resource elements and subframes that wireless device 110 shoulduse to monitor for incoming discovery messages and transmit outgoingdiscovery messages, the received one or more resource poolconfigurations comprising at least a first resource pool configurationreceived from a serving network node of wireless device 110 operating inTDD mode. As another example, receiving module 930 may receive anindication from the serving network node that the particular discoverycarrier does not support system information.

In certain embodiments, wireless device 110 may use FDD. In such a case,receiving module 930 may receive one or more resource poolconfigurations for a particular discovery carrier, the one or moreresource pool configurations comprising information indicating one ormore of resource elements and subframes that wireless device 110 shoulduse to monitor for incoming discovery messages and transmit outgoingdiscovery messages, the received one or more resource poolconfigurations comprising at least a first resource pool configurationreceived from a serving network node of wireless device 110 operating inFDD mode. As another example, receiving module 930 may receive anindication from the serving network node that the paired carrierassociated with the particular discovery carrier does not support systeminformation.

Receiving module 930 may include a receiver and/or a transceiver, suchas transceiver 610 described above in relation to FIG. 6. Receivingmodule 930 may include circuitry configured to wirelessly receivemessages and/or signals. In particular embodiments, receiving module 930may communicate received messages and/or signals to determining module910.

Input module 940 may receive user input intended for wireless device110. For example, the input module may receive key presses, buttonpresses, touches, swipes, audio signals, video signals, and/or any otherappropriate signals. The input module may include one or more keys,buttons, levers, switches, touchscreens, microphones, and/or cameras.The input module may communicate received signals to determining module910.

Display module 950 may present signals on a display of wireless device110. Display module 950 may include the display and/or any appropriatecircuitry and hardware configured to present signals on the display.Display module 950 may receive signals to present on the display fromdetermining module 910.

Determining module 910, communication module 920, receiving module 930,input module 940, and display module 950 may include any suitableconfiguration of hardware and/or software. Wireless device 110 mayinclude additional modules beyond those shown in FIG. 9 that may beresponsible for providing any suitable functionality, including any ofthe functionality described above and/or any additional functionality(including any functionality necessary to support the various solutionsdescribed herein).

FIG. 10 is a block schematic of an exemplary network node 115, inaccordance with certain embodiments. Network node 115 may include one ormore modules. For example, network node 115 may include determiningmodule 1010, communication module 1020, receiving module 1030, and anyother suitable modules. In some embodiments, one or more of determiningmodule 1010, communication module 1020, receiving module 1030, or anyother suitable module may be implemented using one or more processors,such as processor 720 described above in relation to FIG. 7. In certainembodiments, the functions of two or more of the various modules may becombined into a single module. Network node 115 may perform the methodsfor provisioning transmission pools for inter-carrier ProSe directdiscovery described above with respect to FIGS. 1-5.

Determining module 1010 may perform the processing functions of networknode 115. In certain embodiments, network node 115 may use TDD. In sucha case, determining module 1010 may determine a first resource poolconfiguration for a particular discovery carrier, the first resourcepool configuration comprising information indicating one or more ofresource elements and subframes that a wireless device operating in TDDmode should use to monitor for incoming discovery messages and transmitoutgoing discovery messages. As another example, determining module 1010may configure the wireless device to use one of the first resource poolconfiguration or a second resource pool configuration communicated viasystem information of the particular discovery carrier.

In certain embodiments, network node 115 may use FDD. In such a case,determining module 1010 may determine a first resource poolconfiguration for a particular discovery carrier, the first resourcepool configuration comprising information indicating one or more ofresource elements and subframes that a wireless device operating in FDDmode should use to monitor for incoming discovery messages and transmitoutgoing discovery messages. As another example, determining module 1010may configure the wireless device to use one of the first resource poolconfiguration or a second resource pool configuration communicated viasystem information of a paired carrier associated with the particulardiscovery carrier.

Determining module 1010 may include or be included in one or moreprocessors, such as processor 720 described above in relation to FIG. 7.Determining module 1010 may include analog and/or digital circuitryconfigured to perform any of the functions of determining module 1010and/or processor 720 described above. The functions of determiningmodule 1010 may, in certain embodiments, be performed in one or moredistinct modules. For example, in certain embodiments some of thefunctionality of determining module 1010 may be performed by anallocation module.

Communication module 1020 may perform the transmission functions ofnetwork node 115. In certain embodiments, network node 115 may use TDD.In such a case, communication module 1020 may communicate the firstresource pool configuration to the wireless device. As another example,communication module 1020 may communicate an indication to the wirelessdevice that the particular discovery carrier does not support systeminformation. In certain embodiments, network node 115 may use FDD. Insuch a case, communication module 1020 may communicate the firstresource pool configuration to the wireless device. As another example,communication module 1020 may communicate an indication to the wirelessdevice that the paired carrier associated with the particular discoverycarrier does not support system information. Communication module 1020may transmit messages to one or more of wireless devices 110.Communication module 1020 may include a transmitter and/or atransceiver, such as transceiver 710 described above in relation to FIG.7. Communication module 1020 may include circuitry configured towirelessly transmit messages and/or signals. In particular embodiments,communication module 1020 may receive messages and/or signals fortransmission from determining module 1010 or any other module.

Receiving module 1030 may perform the receiving functions of networknode 115. Receiving module 1030 may receive any suitable informationfrom a wireless device. Receiving module 1030 may include a receiverand/or a transceiver, such as transceiver 710 described above inrelation to FIG. 7. Receiving module 1030 may include circuitryconfigured to wirelessly receive messages and/or signals. In particularembodiments, receiving module 1030 may communicate received messagesand/or signals to determining module 1010 or any other suitable module.

Determining module 1010, communication module 1020, and receiving module1030 may include any suitable configuration of hardware and/or software.Network node 115 may include additional modules beyond those shown inFIG. 10 that may be responsible for providing any suitablefunctionality, including any of the functionality described above and/orany additional functionality (including any functionality necessary tosupport the various solutions described herein).

Modifications, additions, or omissions may be made to the systems andapparatuses described herein without departing from the scope of thedisclosure. The components of the systems and apparatuses may beintegrated or separated. Moreover, the operations of the systems andapparatuses may be performed by more, fewer, or other components.Additionally, operations of the systems and apparatuses may be performedusing any suitable logic comprising software, hardware, and/or otherlogic. As used in this document, “each” refers to each member of a setor each member of a subset of a set.

Modifications, additions, or omissions may be made to the methodsdescribed herein without departing from the scope of the disclosure. Themethods may include more, fewer, or other steps. Additionally, steps maybe performed in any suitable order.

Although this disclosure has been described in terms of certainembodiments, alterations and permutations of the embodiments will beapparent to those skilled in the art. Accordingly, the above descriptionof the embodiments does not constrain this disclosure. Other changes,substitutions, and alterations are possible without departing from thespirit and scope of this disclosure, as defined by the following claims.

Abbreviations used in the preceding description include:

AP Access Point

BS Base Station

BSC Base Station Controller

BTS Base Transceiver Station

CDM Code Division Multiplexing

CPE Customer Premises Equipment

D2D Device-to-device

DAS Distributed Antenna System

DL Downlink

eNB evolved Node B

EPDCCH Enhanced Physical Downlink Control Channel

FDD Frequency Division Duplex

LAN Local Area Network

LEE Laptop Embedded Equipment

LME Laptop Mounted Equipment

LTE Long Term Evolution

M2M Machine-to-Machine

MAC Medium Access Control

MAN Metropolitan Area Network

MCE Multi-cell/multicast Coordination Entity

MCS Modulation and Coding Scheme

MSR Multi-standard Radio

NAS Non-Access Stratum

PCell Primary Cell

PDCCH Physical Downlink Control Channel

PDSCH Physical Downlink Shared Channel

PDU Protocol Data Unit

PRB Physical Resource Block

PSSCH Physical Sidelink Shared Channel

PSCCH Physical Sidelink Control Channel

PUSCH Physical Uplink Shared Channel

PUCCH Physical Uplink Control Channel

ProSe Proximity Service

PSTN Public Switched Telephone Network

RB Resource Block

RNC Radio Network Controller

RRC Radio Resource Control

RRH Remote Radio Head

RRU Remote Radio Unit

RSRP Reference Signal Received Power

RX Reception

SA Scheduling Assignment

SCell Secondary Cell

SFN System Frame Number

SIB System Information Block

TDD Time Division Duplex

TX Transmission

UE User Equipment

UL Uplink

WAN Wide Area Network

The invention claimed is:
 1. A method in a wireless device, comprising:receiving one or more resource pool configurations for a particulardiscovery carrier, the one or more resource pool configurationscomprising information indicating one or more of resource elements andsubframes that the wireless device should use to monitor for incomingdiscovery messages and transmit outgoing discovery messages, thereceived one or more resource pool configurations comprising at least afirst resource pool configuration received from a serving network nodeof the wireless device operating in Time Division Duplex (TDD) mode;determining which of the received one or more resource poolconfigurations that the wireless device should use to monitor forincoming discovery messages and transmit outgoing discovery messages;determining whether the particular discovery carrier contains systeminformation; and upon determining that the particular discovery carrierdoes not contain system information, determining whether the wirelessdevice is located at a location where the wireless device is unable toread system information for the particular discovery carrier for aperiod of time; upon determining that the wireless device is not locatedat a location where the wireless device is unable to read systeminformation for the particular discovery carrier for a period of time,determining that the first resource pool configuration received from theserving network node of the wireless device should not be used tomonitor for incoming discovery messages and transmit outgoing discoverymessages; and, upon determining that the wireless device is located at alocation where the wireless device is unable to read system informationfor the particular discovery carrier for a period of time, using thefirst resource pool configuration received from the serving network nodeof the wireless device to monitor for incoming discovery messages andtransmit outgoing discovery messages.
 2. A method in a wireless device,comprising: receiving one or more resource pool configurations for aparticular discovery carrier, the one or more resource poolconfigurations comprising information indicating one or more of resourceelements and subframes that the wireless device should use to monitorfor incoming discovery messages and transmit outgoing discoverymessages, the received one or more resource pool configurationscomprising at least a first resource pool configuration received from aserving network node of the wireless device operating in Time DivisionDuplex (TDD) mode; determining which of the received one or moreresource pool configurations that the wireless device should use tomonitor for incoming discovery messages and transmit outgoing discoverymessages; determining whether system information of the particulardiscovery carrier is broadcast; upon determining that the systeminformation of the particular discovery carrier is not broadcast, usingthe first resource pool configuration received from the serving networknode to monitor for incoming discovery messages and transmit outgoingdiscovery messages; upon determining that the system information of theparticular discovery carrier is broadcast, determining whether thesystem information of the particular discovery channel includes a secondresource pool configuration, and upon determining that the systeminformation of the particular discovery carrier does not include thesecond resource pool configuration, using the first resource poolconfiguration received from the serving network node to monitor forincoming discovery messages and transmit outgoing discovery messages;and, receiving an indication from the serving network node that theparticular discovery carrier does not broadcast system information. 3.The method of claim 2, comprising: upon determining that systeminformation of the particular discovery carrier is not broadcast, usingthe first resource pool configuration received from the serving networknode of the wireless device to monitor for incoming discovery messagesand transmit outgoing discovery messages.
 4. A wireless device,comprising: one or more processors, the one or more processorsconfigured to: receive one or more resource pool configurations for aparticular discovery carrier, the one or more resource poolconfigurations comprising information indicating one or more of resourceelements and subframes that the wireless device should use to monitorfor incoming discovery messages and transmit outgoing discoverymessages, the received one or more resource pool configurationscomprising at least a first resource pool configuration received from aserving network node of the wireless device operating in Time DivisionDuplex (TDD) mode; determine which of the received one or more resourcepool configurations that the wireless device should use to monitor forincoming discovery messages and transmit outgoing discovery messages;determine whether system information of the particular discovery carrieris broadcast; upon determining that the system information of theparticular discovery carrier is not broadcast, use the first resourcepool configuration received from the serving network node to monitor forincoming discovery messages and transmit outgoing discovery messages;upon determining that the system information of the particular discoverycarrier is broadcast, determine whether the system information of theparticular discovery channel includes a second resource poolconfiguration, and upon determining that the system information of theparticular discovery carrier does not include the second resource poolconfiguration, use the first resource pool configuration received fromthe serving network node to monitor for incoming discovery messages andtransmit outgoing discovery messages; and, receive an indication fromthe serving network node that the particular discovery carrier does notbroadcast system information.
 5. The wireless device of claim 4, whereinthe one or more processors are configured to: upon determining thatsystem information of the particular discovery carrier is not broadcast,use the first resource pool configuration received from the servingnetwork node of the wireless device to monitor for incoming discoverymessages and transmit outgoing discovery messages.
 6. A method in anetwork node, comprising: determining a first resource poolconfiguration for a particular discovery carrier, the first resourcepool configuration comprising information indicating one or more ofresource elements and subframes that a wireless device operating in TimeDivision Duplex (TDD) mode should use to monitor for incoming discoverymessages and transmit outgoing discovery messages; communicating thefirst resource pool configuration to the wireless device; andconfiguring the wireless device to use one of the first resource poolconfiguration or a second resource pool configuration communicated viasystem information of the particular discovery carrier; whereinconfiguring the wireless device to use one of the first resource poolconfiguration or the second resource pool configuration comprises oneof: configuring the wireless device to not use the first resource poolconfiguration to monitor for incoming discovery messages and transmitoutgoing discovery messages if the particular discovery carrier does notcontain system information and the wireless device is not located at alocation where the wireless device is unable to read system informationfor the particular discovery carrier for a short period of time; andconfiguring the wireless device to use the first resource poolconfiguration to monitor for incoming discovery messages and transmitoutgoing discovery messages if the particular discovery carrier does notcontain system information and the wireless device is located at alocation where the wireless device is unable to read system informationfor the particular discovery carrier for a short period of time.
 7. Anetwork node, comprising: one or more processors, the one or moreprocessors configured to: determine a first resource pool configurationfor a particular discovery carrier, the first resource poolconfiguration comprising information indicating one or more of resourceelements and subframes that a wireless device operating in Time DivisionDuplex (TDD) mode should use to monitor for incoming discovery messagesand transmit outgoing discovery messages; communicate the first resourcepool configuration to the wireless device; configure the wireless deviceto use one of the first resource pool configuration or a second resourcepool configuration communicated via system information of the particulardiscovery carrier; configure the wireless device to not use the firstresource pool configuration to monitor for incoming discovery messagesand transmit outgoing discovery messages if the particular discoverycarrier does not contain system information and the wireless device isnot located at a location where the wireless device is unable to readsystem information for the particular discovery carrier for a shortperiod of time; and configure the wireless device to use the firstresource pool configuration to monitor for incoming discovery messagesand transmit outgoing discovery messages if the particular discoverycarrier does not contain system information and the wireless device islocated at a location where the wireless device is unable to read systeminformation for the particular discovery carrier for a short period oftime.
 8. The method of claim 1, further comprising: switching, based onwhether system information is not received by the wireless device for aparticular duration, from a behavior in which the wireless device shouldnot use the first resource pool configuration received from the servingnetwork node to monitor for incoming discovery messages and transmitoutgoing discovery messages to a behavior in which the wireless deviceuses the first resource pool configuration received from the servingnetwork node of the wireless device to monitor for incoming discoverymessages and transmit outgoing discovery messages.
 9. The method ofclaim 1, further comprising: switching, based on determination that anS-criterion is not fulfilled for a particular duration, from a behaviorin which the wireless device uses the first resource pool configurationreceived from the serving network node of the wireless device to monitorfor incoming discovery messages and transmit outgoing discovery messagesto a behavior in which the wireless device should not use the firstresource pool configuration received from the serving network node tomonitor for incoming discovery messages and transmit outgoing discoverymessages.
 10. A wireless device, comprising: one or more processors, theone or more processors configured to: receive one or more resource poolconfigurations for a particular discovery carrier, the one or moreresource pool configurations comprising information indicating one ormore of resource elements and subframes that the wireless device shoulduse to monitor for incoming discovery messages and transmit outgoingdiscovery messages, the received one or more resource poolconfigurations comprising at least a first resource pool configurationreceived from a serving network node of the wireless device operating inTime Division Duplex (TDD) mode; determine which of the received one ormore resource pool configurations that the wireless device should use tomonitor for incoming discovery messages and transmit outgoing discoverymessages; determine whether the particular discovery carrier containssystem information; and upon determining that the particular discoverycarrier does not contain system information, determine whether thewireless device is located at a location where the wireless device isunable to read system information for the particular discovery carrierfor a period of time; upon determining that the wireless device is notlocated at a location where the wireless device is unable to read systeminformation for the particular discovery carrier for a period of time,determine that the first resource pool configuration received from theserving network node of the wireless device should not be used tomonitor for incoming discovery messages and transmit outgoing discoverymessages; and, upon determining that the wireless device is located at alocation where the wireless device is unable to read system informationfor the particular discovery carrier for a period of time, use the firstresource pool configuration received from the serving network node ofthe wireless device to monitor for incoming discovery messages andtransmit outgoing discovery messages.